This application note explains loopback function of AFE79xx TI transceiver. This application note highlights the features and performance of AFE79xx as indigenous single chip repeater function for achieving low latency signal loopback using normal RX, TX pair and fast signal loopback using RX feedback and TX pair.

The application note includes the following key points.

• Understanding and configuring internal loopback JESD and fast loopback modes of AFE79xx.
• Measuring Group delay and Gain response across different data rates highlighting minimum latency sub 2 us and flat passband response for applied wideband spectrum bandwidth.
• Measuring Fast Feedback Analog Loop response Group delay to achieve sub 50-ns group delay response for applications demanding lowest latency in wide bandwidth (1 GHz) repeater signal chain application